QUIZ – 2020: INSIGHTS STATIC , 13 April 2021 – Environment

Solution: a)

Epiphytic (plants growing on other plants including those growing on rock boulders and often termed lithophyte),

Terrestrial (plants growing on land and climbers)

Mycoheterotrophic (plants which derive nutrients from mycorrhizal fungi that are attached to the roots of a vascular plant).

Solution: c)

Ocean is a self-sustaining ecosystem and covers nearly 2/3^rd of earth’s area. It is the oldest ecosystem. It is least affected by natural calamities.

It is a highly diverse (from phytoplankton to sea grass to whales) and productive ecosystem and contains earliest evolutionary life forms. The evolutionary history has also been more stable than in terrestrial environments.

Solution: d)

What is so special about tropics that might account for their greater biological diversity? Ecologists and evolutionary biologists have proposed various hypotheses; some important ones are

(a) Speciation is generally a function of time, unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and thus, had a long evolutionary time for species diversification,

(b) Tropical environments, unlike temperate ones, are less seasonal, relatively more constant and predictable. Such constant environments promote niche specialisation and lead to a greater species diversity and

(c) There is more solar energy available in the tropics, which contributes to higher productivity; this in turn might contribute indirectly to greater diversity.

Solution: a)

In an aquatic ecosystem, grazing food chain is the major conduit for energy flow. As against this, in a terrestrial ecosystem, a much larger fraction of energy flows through the detritus food chain than through the grazing food chain.

When energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed. Around 90% of energy will be lost.

Solution: b)

Alpha diversity

Alpha diversity describes the species diversity within a community at a small scale or local scale, generally the size of one ecosystem. When we casually speak of diversity in an area, more often than not it refers to alpha diversity.

Beta diversity

Beta diversity describes the species diversity between two communities or ecosystems. It is at a larger scale, and looks to compare the species diversity between two separate entities that are often divided by a clear geographical barrier like a river or a mountain ridge.

Gamma diversity

Gamma diversity is studied at a very large scale—a biome—where species diversity is compared between many ecosystems. It could range over areas like the entire slope of a mountain, or the entire littoral zone of a sea shore.

Example: Let’s take a mountain slope as our landscape. On this slope, there will be many different patches of forests and grasslands. Alpha diversity is the species diversity present within each forest or grassland patch of the slope. Beta diversity is represented by the species diversity between any two patches and their communities. Gamma diversity of the landscape is the species diversity along the entire range of the mountain slope.

Food web is more comprehensive than food chain.